Okhotsk express & Ryuhyo express

I saw that there is a special train from Sapporo to Abashiri called the Ryuhyo Express (Okhotsk-no-kaze) from end January to end February. The usual Okhotsk limited express is running as per usual also. Anyone knows what the difference between the trains are and whether it would be worth it to take the special train?

It has a different train set. They call it a "resort train". It seems to have larger windows, a lounge car and to be newer than the regular trains to Abashiri.

If you have a choice time wise, I would go for the special train, but if not, then I think you won't miss too much.

Here are some pictures:
http://www.jrhokkaido.co.jp/travel/ryuhyo/train.html